MOGADISHU, Somalia — A bomb exploded Monday in a van carrying UN employees in northern Somalia, killing at least seven people and wounding several others, police and UN officials said. Al-Shabab claimed responsibility for the attack.

UNICEF said in a statement that four of its employees were reportedly killed in the bombing of their van, which was painted white and had UN painted on the side in blue letters. Four others were seriously injured, the UN children’s agency said.

Both foreigners and Somalis were casualties of the attack in Garowe, the capital of the semiautonomous Puntland region, Col. Ali Salad, a senior police officer in Puntland, told the Associated Press by phone. He said 10 people had died, though Garowe Police Chief Col. Ahmed Abdullahi Samatar said seven died.

Somali President Hassan Sheikh Mohamud called it a direct attack on the future of the country.

“This attack is not just targeted at the United Nations, but in attacking UNICEF, al-Shabab has also attacked Somali children. It is an attack against the future of our country and I condemn it in the strongest possible terms,” Mohamud said in a statement.

A UN employee in Garowe, who insisted on anonymity because she is not authorized to speak to the press, said most of the victims are foreigners working with the UN.

The bomb was apparently planted under a seat and was detonated by remote control, said police official Yusuf Ali.

Garowe resident Jama Hashi said he heard a thundering blast inside the van, which he said was passing near the offices of the UN’s food agency when the bomb went off. Human limbs were scattered around the scene, he said. Security forces sealed off the area as ambulances carried the wounded away.

“It’s a dark day, but terrorists must know that the blood they shed will not go in vain. We shall deal with them with an iron hand,” Salad said.

Bombings are not common in northern Somalia, unlike in the south, where al-Shabab Islamic extremists are fighting the Somali government and the African Union forces bolstering it.